1. Field of the Invention
The present invention relates to an integrated circuit (IC) for driving a halogen lamp.
2. Brief Description of the Related Art
FIG. 1 shows a conventional halogen convertor circuit 10 for driving a halogen lamp (not shown) connected across output leads 12 to a secondary coil of transformer 14. Circuit 10 receives AC power across input leads 16, and functions as a basic bipolar self-resonating circuit, but with limited performance.
Integrated circuits (ICs) have been developed to provide electronic ballast controllers for fluorescent lamps. A conventional ballast IC can, for example, include an oscillating half bridge driver, fault logic that responds to signals indicating fault conditions, and other appropriate circuitry for starting and running a fluorescent lamp. An example is the IR2156 IC sold by International Rectifier Corporation (IR) and described in U.S. Pat. No. 6,211,623, the disclosure of which is incorporated herein by reference in its entirety.
Ballast ICs for fluorescent lamps are not, however, suitable for driving other types of lamps, such as halogen lamps and other lamps with filaments (referred to herein as “filament lamps”). It would be advantageous to provide an IC for driving a filament lamp and, more particularly, a halogen lamp.